Method and apparatus for controlling the intake of shipboard air in response to airborne contamination



Feb. 11, 1964 c. N. CLARK ETAL 3,120,796

METHOD AND APPARATUS FOR CONTROLLING THE INTAKE OF SHIPBOARD AIR IN RESPONSE TO AIRBORNE CONTAMINATION Filed March 20, 1961 2 Sheets-Sheet I Fig. I

INVENTORS CHARLIE IV CLARK 04 1 /0 (NM/l Lulu C. N. CLARK ETAL METHOD AND APPARATUS FOR CONTROLLING THE Feb. 11, 1964 3,120,796

INTAKE 0F SHIPBOARD AIR IN RESPONSE TO AIRBORNE CONTAMINATION 2 Sheets-Sheet 2 Filed March 20; 1961 INVENTORS CHARLIE N. CLARK United States Patent 3,126,796 METHfiD AND APPARATUS 358R CGNTROLLENG THE INTAKE 0F SHWBOARD AIR lhl RESEONSE T0 AIRBORNE CUNTAWENATION Charlie N. Clark, 410 Broderick St., and David Linn, 173 Hamerton Stu, hath of San Francisco, Calif. Filed Mar. 20, 1961, Ser. No. 97,111 '7 Claims. (Cl. 98-1) (Granted under Title 35, US. Code (i952), sec. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates generally to a method for controlling a ships ventilating system. More specifically, it. covers a method and apparatus for protecting naval \essels against airborne contamination damage resulting from atomic, bacteriological and chemical attacks.

In case of a naval engagement or approximate atomic attack, even though no direct physical damage to the ship structure results, the prevention of injury to personnel aboard as a result of exposure to fallout is of vital importance. Normally, compartment access openings such as hatches and port holes would be manually closed by the ships personnel. Machinery openings such as intakes to forced draft blowers for directing air to fire boxes and the like may be left open to permit the ship to depart from the danger zone. Any contamination resulting therefrom may be corrected by the standard wash down to remove radiological particles resulting from an atomic blast.

The real danger to the personnel would result from the admission of contaminated air through the ships ventilating system. Although ventilating fans may be stopped to prevent rapid flow of air through the system, nevertheless, minor air movements through the various ventilation Weather openings, as a. result of the ships movement or temperature changes, may continue.

Various types of closures have been proposed, some of a semi-automatic construction, but the cost and weight of said closures are quite prohibitive, especially due to the great number of openings to be blocked in an emergency.

The general object of the present invention is to provide a method and apparatus for automatically sensing and indicating the presence of radiological fall-out in injurious concentrations and then manually or automatically blocking all ventilating duets with inflatable balloon closures during the period of said injurious concentration and washing down the exposed exterior portion of the ducts exposed to the fall-out, after the sensing elements indicate all-clear and before deflating the balloon closures to open the ducts.

One of the objects of this invention is to provide a means for blocking or closing the present ventilating air ducts on a ship without changing the duct structure or design.

Another object is to provide means for actuating a plurality of said duct closures simultaneously by a central control operating system.

Still another object is to provide a detecting system comprising a plurality of radiological or chemically responsive sensing elements at strategic points about the ship for indicating the critical contamination level w ereby the operating system may be manually or automatically controlled to close the ventilating ducts.

A further object is to provide means for washing down the entrance sections of the ventilating ducts between the closure and the opening after the all-clear signal is received and before the closure is deflated to open the ice entrance of the ventilating duct for the admission of air free of foreign matter.

A further object is to provide operative means in said system for supplying pressure fluid for inflating the balloon closures.

Another object is to provide standby means in the system for inflating the enclosures in case the operative means for supplying the pressure fluid fails to function during the emergency.

Another object is to provide means in said system for automatically shutting off the duct fans under the control of the sensing device.

The overall purpose of the subject invention is to provide a method and apparatus for preventing contaminated air from entering a ships ventilating system and provide means for controlling said apparatus by a plurality of sensing devices located at strategic points about the ship for detecting injurious concentrations of such impurities. Finally the method for handling the abnormal condition to exclude admission of the foreign matter during the emergency also includes the step of washing down the duct entrance after the all-clear signal is re ceived but before the closure is deflated to re-open the duct for the admission of pure air free of foreign matter.

With these and other objects in view, as will hereinafter more fully appear, and which will be more particularly pointed out in the appended claims, reference is now made to the following description taken in connection with the accompanying drawings in which:

FIG. 1 is a schematic diagram of the apparatus for protecting naval vessels against air-borne contamination damage resulting from atomic, bacteriological and chemical attacks; and

FIG. 2 is a circuit diagram of the automatic control s stem.

In detail, ducts l1 and 36 are the entrance portion of ducts connected to a ships ventilating system through which outside air is induced to flow by means of the induced draft fan as. In duct 11, closure 12 is provided near the entrance 47 and is adapted to be indated by pressure fluid supplied from the header 24 through pipe 13. Said closure 12 (shown in broken lines), when inflated will fill the cross-section of the duct 11 as indicated by the phantom lines. In the same manner, closure 37 is located in duct 36 near its entrance 43 and is inflated by pressure fluid supplied through pipe 38 from header 14.

The pressure fluid source is supplied to tank 16 by a compressor 17 driven by an electric motor 18 connected to the ships power supply 19. A pressure cut-off valve 21 is provided in the line connecting the compressor 17 to the tank 16 to open the motor circuit when maximum pressure is reached. Pressure relief valves 22 and 23 are provided on the tank 16 and header or manifold 14 respectively to prevent excess pressure build up.

The tank 16 is connected to the manifold 14 through valves 24 and 27. Valve 2a is manually controlled and may be operated in response to visual indicator 33. Valve 27 is an electrically operated or solenoid valve automatically controlled by the detecting device 32 which in turn is actuated by one or more sensing elements 31 located at strategic points about the ship. Opening said pressure valve 2-4 or 27 connects the pressure fluid source 3.7 of tank 16 to the manifold 14.

An emergency pressure fluid source is provided in case the above described source from tank 16 fails. "l." he emergency source comprises a bottled gas container 28 of CO or other suitable pressure fluid. Such an emergency source of operating fluid is manually controlled by valve 29 which is opened in response to the visual indicator 33.

The valve 26 is shown as a manually controlled valve for releasing the pressure fluid and deflating closures l2 and 37 in response to an all clear indication on 33. However, solenoid valve 25 may be electrically connected directly to the control device 323 for automatic operation whereby the all-clear signal followed by the wash down will deflate all closures and return the ships ventilating system to normal operation, such as by starting the ships main ventilating fan 46.

The wash down step is provided by a system comprising a water pressure source 34 connected through pipes 39 and 41 to wash down nozzles 42 and 43 respectively located in ducts l1 and 36 between the respective balloon closures and duct entrances 47 and 48. Valve 44 may be manually operated in response to indicator 33 or the system may be made automatic by means of solenoid valve 45 actuated by the detecting control device 32.

In operation, assuming the ship is located in an area Where airborne contamination damage may result from atomic, bacteriological or chemical attacks, the proposed system will function as follows. For example, in case atomic fallout is present radiological particles exist in iniurious concentrations, one or more of the sensing elements 31 about the ship would detect this state and signal the central detecting or control device 32 where the alert visual indicator 33 would respond. The solenoid valve 27 would immediately open permitting the pressure fluid from tank 16 to enter manifold M which is connected to balloon closure 12 by pipe 13 and closure 37 through pipe 38. The fiuid inflates both closures until they close their. respective ducts 1i and 36 by conforming to the duct cross-section at this point, whether the cross-section be circular, oval, or irregular. The above condition is maintained until the sensing element 31 indicates an all clear condition.

In the above described step, in case the automatic valve 27 were not present, then the manual valve 24 would be opened when the visual indicator 33 showed the injurious condition present. Also, if pressure fluid supply had been disrupted the valve 2% could be manually opened to admit pressure fluid from the emergency source 28. Although probably impractical, the closures may be inflated manually by any suitable pressure means replacing tank 28.

When the all-clear signal is received by the indicator 33 from the sensing elements 31 automatic operation would first open solenoid valve 45 to permit water under pressure from supply 34 to connect to nozzles 42 and 3-3 by pipes 39 and ll in order to wash down the ent ance portion of the ducts. Immediately after the wash down the solenoid valve 25 would open to deflate closures 12 and 37 thereby reestablishing the ships ventilating system to normal operation.

Both automatic steps of Washing down the duct entrance and then deflating the closures as described above may be controlled manually by valve 44 and valve 26 respectively in response to the visual indicator 33, and the main ventilating fan 46 started.

The central control device for automatically operating the system is diagrammatically illustrated in FF. 2 and its operation sequence is as follows. The power feed lines 49 from the supply 1% connect to the central control device 32.. The sensing device 31 is basically an open switch which closes when the presence of radiological fall-out in injurious concentrations occur. The closing of sensing switch 31 which is the first step in the sequence energizes visual indicator 33 and a normally-open, circuit closing control relay 51. Control relay i. closes a similar relay 52 which opens pressure valve 27 admitting pressure fluid from storage tank 16 through manifold M to balloon closures 12 and 37.

During this first step, namely inflation of the balloon closures, the circuitry components of the second step in the sequence are shifted for the wash down operation. F or example, normally closed circuit opening control relay 55 is opened and a normally open, circuit closing relay 53 is closed which in turn closes time delay relay 5% and time opening switch which is another circuit closing relay. Thereafter, when all is clear and the sensing switch 31 opens, relay 55 will close and wash down valve 45 will be energized and opened to permit water under pressure to be sprayed by nozzles 32 and 2-3 into the duct entrances 47 and 48 to wash out any deposited radiological fallout before reopening the ducts. The length of period of the Wash down operation will be controlled by tim delay rela which starts its timing cycle when relay 53 opens on all clear from 31. As time delay relay 54 times out it opens relay 56 thus closing water pressure valve 4:? to terminate the wash down cycle.

Termination of the wash down cycle will start time delay relay 57' on its timing cycle to initiate the third step in the sequence, namely, deflating the balloon closures by releasing the manifold pressure through valve 25. As time delay relay 54 times out to terminate the wash down cycle it de-energizes 59 thereby permitting it to assume its normally closed position. Time delay relay 57 which started its timing function at the end of the wash down cycle closes contact 53 to complete the deflating circuit and open the deflation valve 25 which remains open during the timing cycle of time delay relay 57 and then automatically closes when 58 is opened. Valve 25 remains in its normally closed position until the wash down step is completed during a subsequent cycle operation.

Summarily, when sensing element 31 is closed as a result of the presence of radiological particles the visual indicator 33 is immediately energized and at the same instant relays 51, 52 and 53 are closed and relay 55 is opened. The closing of relay 52 opens pneumatic pressure valve to inliate the enclosures 12 aand 37. The above condition namely inflate prevails so long as sensing element 31 is closed.

When sensing element 31 opens on all clear the second step or wash down follows, namely, relay 55 is normally closed and as 53 opens the time delay 54 starts cycle by closing time 0 setting relay 56 which opens water pressure valve as and continues to wash down ventilator entrances 4-7 and 43 until relay 54 has timed out.

The third step or deflation of closures starts when relay 54 has timed out thus opening 56 and starting time delay relay 57 on its operating cycle by closing time opening relay 53 and opening pneumatic pressure release valve 25 through normally closed relay 59. When time delay relay 57 has timed out, relay 5% opens and allows valve 25 to close thus returning the system to neutral ready for reinflation upon sensing of radiological particles anew.

The above description employs a sensing element 31 of any conventional type used for detecting radiological particles. By changing the type of element 31 to one sensitive to bacteriological or chemical contamination, or a combination of foreign substances, the rest of the ventilating system control will continue to function as described above under operation, regardless of the selected sensing element.

It should be understood, of course, that the foregoing disclosure relates to only a preferred embodiment of the invention and that it is intended to cover all changes and modifications of the example of the invention herein chosen for the purpose of the disclosure, which do not con stitute departures from the spirit and scope of the invention.

What is claimed is:

1. An apparatus for preventing air contaminated with foreign matter such as radio-active particles in injurious concentrations from entering the ducts of a ships ventilating system comprising a ship equipped with a system of ventilating ducts extending from the exterior surface of a'ship to the interior thereof, an inflatable closure located in each duct adjacent its exterior entrance, a pressure fluid source for inflating said closures, sensing devices located at one or more strategic points on the exterior of the ship for detecting the presence of foreign matter in injurious concentrations, control means actuated by said sensing device for automatically connecting said pressure fluid source to all closures simultaneously so that said foreign matter is included from entering the ventilating system.

2. An apparatus for preventing air contaminated with foreign mater in injurious concentration from entering the ducts of a ships ventilating system comprising a ship equipped with a system of ventilating ducts extending from the exterior surface of a ship to the interior thereof, an inflatable closure located in each duct adjacent its exterior entrance, a controlled pressure fluid source connected to said closures for inflating said closures, sensing devices located at one or more strategic points on the exterior of the ship for detecting the presence of foreign matter in injurious concentrations, indicating means for signalling the presence of foreign matter in injurious concentrations, control means for connecting said pressure fluid source to all closures simultaneously when it is indicated that said foreign matter exists in injurious concentration, means for washing down that portion of the duct between the entrance and the closure to remove any foreign matter in all ducts adjacent their exterior entrance after the all-clear indication is received and prior to the deflation of the closure for the admission of air free of foreign matter into the ventilating system.

3. An apparatus as in claim 2 wherein said control means also includes means for automatically deflating said closures after the wash down period is terminated.

4. An apparatus for preventing air contaminated with foreign matter in injurious concentrations from entering the ducts of a ships ventilating system comprising a ship equipped with a system of ventilating ducts extending from the exterior surface of a ship to the interior thereof, an inflatable closure located in each duct adjacent its exterior entrance, sensing devices located at one or more strategic points on the exterior of the ship for detecting the presence of foreign matter in injurious concentrations, and a control system actuated by said sensing device including means for automatically inflating said closures during the presence of said foreign matter in injurious concentrations.

5. An apparatus as in claim 4 wherein said control system includes means for automatically washing down the duct entrances during a fixed period after the concentra tion of foreign matter has dropped to a noninjurious point, said apparatus further including means for deflating the closures so that the residual deposit of foreign matter left in the duct entrance will be washed away.

6. A method for centrally controlling and preventing air contaminated with radioactive particles in injurious concentration from entering the ducts of a ships ventilating system comprising the steps of locating an inflatable closure at the entrance of each ventilating duct of a ships ventilating system, fitting said closure to its respective duct so that its inflatable size will be large enough to conform to the unmodified cross-section of the respective duct to be closed, detecting the presence of radioactive particles in injurious concentrations by means of sensing elements located at a plurality of critical points about the ship, indicating at a central control point the presence of radioactive particles in injurious concentrations at any critical point, connecting a pressure fluid source to all closures in response to an indication of radioactive particles in injurious concentrations at any critical point so that said closure will be inflated to fill and close the ducts at the entrance thus preventing contaminated air from entering the ships ventilating system, indicating at the central control point an all-clear signal when the airborne radiaactive particles fall below the level of injurious concentrations, then washing down the section of all ventilating ducts between the entrance and inflated closure to remove the radioactive particles, and finally deflating the closures to open the entrance of said ventilating ducts so that the ventilating system may be returned to normal operation after the contamination has passed.

7. An apparatus for preventing air contaminated with foreign matter in injurious concentrations from entering the ducts of a ships ventilating system comprising, a ship, a system of ventilating ducts extending from the exterior surface of the ship to the interior thereof, an inflatable closure located in each duct adjacent its exterior entrance, sensing devices located at one or more strategic points on the exterior of the ship for detecting the presence of foreign matter in injurious concentrations, and a control system actuated by said sensing devices including means for automatically inflating said enclosures during the presence of said foreign matter in injurious concentrations, said control further including means for automatically washing down the duct entrances during a fixed period after the concentration of foreign matter has dropped to a noninjurious point so that the residual deposit of foreign matter left in the duct entrance will be .washed away, and means for automatically deflating the closures after the wash down period is terminated.

References Cited in the file of this patent UNITED STATES PATENTS 2,295,728 Gess Sept. 15, 1942 2,801,067 Mercier Iluly 30, 1957 2,878,824 Swanson Mar. 24, 1959 2,892,091 Sawle June 23, 1959 2,912,920 Coe Nov. 17, 1959 2,979,620 Bradshaw et a1 Apr. 11, 1961 2,995,335 Raftis Aug. 8, 1961 FOREIGN PATENTS 187,153 Switzerland J an. 2, 1937 

6. A METHOD FOR CENTRALLY CONTROLLING AND PREVENTING AIR CONTAMINATED WITH RADIOACTIVE PARTICLES IN INJURIOUS CONCENTRATION FROM ENTERING THE DUCTS OF A SHIP''S VENTILATING SYSTEM COMPRISING THE STEPS OF LOCATING AN INFLATABLE CLOSURE AT THE ENTRANCE OF EACH VENTILATING DUCT OF A SHIP''S VENTILATING SYSTEM, FITTING SAID CLOSURE TO ITS RESPECTIVE DUCT SO THAT ITS INFLATABLE SIZE WILL BE LARGE ENOUGH TO CONFORM TO THE UNMODIFIED CROSS-SECTION OF THE RESPECTIVE DUCT TO BE CLOSED, DETECTING THE PRESENCE OF RADIOACTIVE PARTICLES IN INJURIOUS CONCENTRATIONS BY MEANS OF SENSING ELEMENTS LOCATED AT A PLURALITY OF CRITICAL POINTS ABOUT THE SHIP, INDICATING AT A CENTRAL CONTROL POINT IN THE PRESENCE OF RADIOACTIVE PARTICLES IN INJURIOUS CONCENTRATIONS AT ANY CRITICAL POINT, CONNECTING A PRESSURE FLUID SOURCE TO ALL CLOSURES IN RESPONSE TO AN INDICATION OF RADIOACTIVE PARTICLES IN INJURIOUS CONCENTRATION AT ANY CRITICAL POINT SO THAT SAID ENTRANCE THUS PREVENTING CONTAMINATED AIR FROM ENTERING THE SHIP''S VENTILATING SYSTEM, INDICATING AT THE CENTRAL CONTROL PLANT AN ALL-CLEAR SIGNAL WHEN THE AIRBORNE RADIAACTIVE PARTICLES FALL BELOW THE LEVEL OF INJURIOUS CONCENTRATIONS, THEN WASHING DOWN THE SECTION OF ALL VENTILATING DUCTS BETWEEN THE ENTRANCE AND INFLATED CLOSURE TO REMOVE THAT RADIOACTIVE PARTICLES, AND FINALLY DEFLATING THE CLOSURES TO OPEN THE ENTRANCE OF SAID VENTILATING DUCTS SO THAT THE VENTILATING SYSTEM MAY BE RETURNED TO NORMAL OPERATION AFTER THE CONTAIMINATION HAS PASSED. 